#include <stdio.h>
#include <math.h>
#define NUM 320
int number[NUM];
int main()
{
    int i, j, count = 0;
    printf("there are following primes sequences in first row:\n");
    for (j = 0, i = 3; i <= 1993; i += 2)
        if (fflag(i))
            number[j++] = i;
    for (j--; number[j] > 1898; j--)
    {
        for (i = 0; number[j] - number[i] > 1898; i++)
            if (number[j] - number[i] == 1898)
                printf("(%d) %3d,.......,%d\n", ++count, number[i], number[j]);
    }
}
fflag(i) 
int i;
{
    int j;
    if (i <= 1)
        return 0;
    if (i == 2)
        return 1;
    if (!(i % 2))
        return 0;
    for (j = 3; j <= (int)(sqrt((double)i) + 1); j += 2)
        if (!(i % j))
            return 0;
    return 1;
}